The HT Mega – Absolute Addons For Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'block_css' and 'inner_css' parameters in all versions up to, and including, 2.7.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://plugins.trac.wordpress.org/changeset/3209697/ht-mega-for-elementor